Start frame delimiter
||It has been suggested that this article be merged into Ethernet frame. (Discuss) Proposed since February 2014.|
The Start Frame Delimiter (SFD) is the 8-bit (1-byte) value marking the end of the preamble, which is the first field of an Ethernet packet, and indicating the beginning of the Ethernet frame. The SFD is immediately followed by the destination MAC address, which is the first field in an Ethernet frame. SFD has the value of 171 (10101011 in binary notation).:sections 3.1.1 and 3.2
The preamble of an Ethernet packet consists of a 56-bit (7-byte) pattern of alternating 1 and 0 bits, which allows devices on the network to easily detect a new incoming frame. The SFD is designed to break this pattern and signal the start of the actual frame.:section 4.2.5
- "802.3-2012 - IEEE Standard for Ethernet" (PDF). ieee.org. IEEE Standards Association. 2012-12-28. Retrieved 2014-02-08.